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posted by Arnaud THOUAND at Sep 24, 2018 12:08 PM
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Dear Sebastien,

Up to now, it is indeed always a factor 2. I don't encounter the problem when simulating the GEO environment but only when simulating the other environments. I am using SPIS 5-1-8.

Regards, Arnaud

posted by Sébastien Hess at Jul 31, 2018 11:29 AM
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Dear Arnaud,

Is it always a factor of 2? What can happen is a problem with the current predictors of SPIS. SPIS tries to adapt its time steps to prevent the numerical noise on current from introducing large changes on the potential (that is why the time steps may be small at some time). However, given the complexity of plasma physics, it is sometimes hard to make the difference between "real" currents and noise, which leads to localized (in time) jumps of the potential. This happens in particular close to convergence when the currents from the main populations cancel leaving space for the more noisy secondary current to perturb the potential.

Could you tell us the version of SPIS you use?

Cordially,

Sébastien

posted by Arnaud THOUAND at Jul 17, 2018 5:52 PM
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Hello and thank for your time,

I am simulating a spacecraft charging over time in a GEO environment, a DMSP combined spectra environment and a Cold single Maxwelliand and Fontheim Electrons environments.

However, I encounter problems.

During my different simulations, it happens that during one time step incrementation, the time is lower than usual and all average surface potential of node 1 to 8 aremultiplicate by 2. For node 1, if the incrementation for one time step is 2V, and the jump happens when the node 1 is at 20 V, then the new node 1 voltage will be 20*2+2=42V after the time step incrementation.

Is there any reason it should happen?

Thank you, Arnaud